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Caterpillar 252B Troubleshooting

The Cat 252B skid steer loader driveline system components: a 201.2 cu.in (3.3L) Caterpillar 3044C DIT 4-cycle 4-cylinder turbocharged diesel engine with a rated power of 70 hp (52 kW), and 1-speed or 2-speed hydrostatic transmission. The hydraulic system has a pump with a rated capacity of 21.9 gal/min (83 l/min). The system pressure is 3335 psi (230 bar). The Cat 252B is equipped with wet multi disc brakes, 100HS roller chains, and 12x16.5 tires. The skid steer loader has a lift height of 126.3" (3210 mm) to hinge pin and dump height of 95.2" (2420 mm). The rated operating capacity is 2500 lbs (1135 kg), and tipping load is 5615 lbs (2545 kg).

Engine Troubleshooting

Engine starts hard or will not start
Air in fuel system - Bleed fuel system.
Fuel filter element clogging - Filter maintenance required.
Fuel injection nozzles are damaged - If necessary, replace with a new nozzle.
Water in the fuel system - Change fuel and repair fuel system.
Valve clearance is out of adjustment - Adjust valve clearance according to specifications.
Defective fuel injection pump - Install a new pump or rebuild.

Engine starts but then stops
Air filter is clogged - Replace or clean air filter element.
Fuel filter element is dirty - Replace the filter element.
Poor fuel injection pump tightness - Look for any leaks of fuel pump, tighten it fast.
Clogged or defective injectors - Clean or replace fuel injectors.
Fuel injection pump is faulty - Repair or replace injection pump.

Engine shuts off suddenly during operation
Coolant temperature is low - Warm up engine as required.
Fuel filter element is dirty - Clean the filter or install new filter element.
Air in the fuel system - Air bleeding.
Defective or clogged injection nozzle - Inspect nozzles and replace if necessary.
Wrong setting of fuel injection pump timing - Adjust as recommended.

Engine stops at idle
Wrong adjustment of low idle speed - Test and adjust.
Fuel injection pump is not operating properly - Replace or repair injection pump.
Defective fuel injectors - Clean fuel injectors or change it.
Valve out of adjustment - Adjust valve clearance.

Diesel engine is losing power
Air cleaner is clogged - Install new air cleaner element.
Fuel injection nozzles fault - Inspect nozzles and replace if necessary.
Fuel injection pressure is wrong - Adjust to correct pressure.
Valve out of adjustment - Check and adjust.
Incorrect low idle speed adjustment - Correct low idle settings.
Dirt in the fuel hoses or lines - Clean fuel lines and hoses.
Defective cylinder head gasket - Install a new gasket.
Leaking or defective piston rings - Replace piston rings.

Engine overheated
Low engine coolant - Add coolant and check the components of cooling system.
Insufficient engine oil - Fill up the oil to required level.
Clogged radiator core or damaged radiator cap - Replace cap or clean radiator.
Fan belt slipping or worn - Install new fan belt.
Engine overloaded - Reduce load on the engine.

Oil pressure is low
Lack of oil - Fill up the engine oil.
Oil filter is clogged - Replace or clean engine oil filter element.
Oil grade or viscosity is wrong - Fill up with the proper oil viscosity.
Incorrect oil clearance in main bearing - Bearing needs to be changed.
Oil pump failure - Remove and inspect oil pump.

Engine noises or knocks
Engine oil level is low - Fill up the oil to required level.
Engine is not warmed up to the required temperature - Warm up the engine.
Improper setting of fuel injection pump timing - Adjust the pump as required.
Incorrect low idle setting - Normalize low idle speed.
Fuel injectors are faulty or clogged - Inspect fuel injectors and change as required.
Connecting rod is not aligned or defective - Replace or align connecting rod.
Scored or worn pistons - Pistons replacement required.

Drive System Troubleshooting

Machine is not moving in one direction or either direction
Hydraulic oil level is low - Need to add oil.
Drive chain malfunction - Inspect drive chain and replace faulty components.
Input drive shaft is faulty - Replace drive shaft.
Worn or damaged relief valve - Change or repair relief valve.
Plugged suction line or hydraulic filter - Change hydraulic filter or service suction line.
Defective or worn foot or hand controls - Change or repair.
Drive pump or motor malfunction - Repair or change faulty component.

Loss of power
Hydraulic oil filter is dirty - Change or clean hydraulic filter.
Faulty or opened relief valve - Change or close relief valve.
Transmission parts are faulty or damaged - Check and change defective components.
Input drive shaft is worn - Repair or replace drive shaft.
Air leaks in hydraulic system - Bleed air from system.

Drive system keeps overheating
Insufficient hydraulic fluid - Checking hydraulic fluid level and add if necessary.
Dirty hydraulic fluid filter - Check, clean, or replace as required.
Relief valve is worn or damaged - Repair or replace relief valve.
Damaged drive pump or hydraulic motor - Replace or repair faulty component.
Oil cooler is clogged - Clean cooling fins as required.
Drive system is overloaded - Load needs to be reduced.

Drive system makes excessive noise
Wrong oil viscosity - Use oil of correct viscosity.
Air in the hydraulic system - Bleed air from hydraulic system.
Damaged drive pump or hydraulic motor - Repair or change faulty component.
Mechanical parts of drive system are defective or worn - Check the components and change if necessary.

Hydraulics Troubleshooting

Hydraulic system is overheated
Hydraulic pressure incorrectly adjusted - Adjust it correctly.
Main relief valve is damaged or adjusted improperly - Replace or set up the relief valve.
Dirty hydraulic fluid - Hydraulic fluid change required.
Hydraulic oil level is insufficient - Fill up the hydraulic oil.
Hydraulic pump is faulty - Replace or repair pump if necessary.

Lift arm cannot be raised or lowered
Faulty lift controls - Inspect and repair if necessary.
Hydraulic pump failure - Install new pump or repair it.
Defective hydraulic control valve - Repair or change hydraulic valve.
Faulty hydraulic cylinder - Install a new boom cylinder or repair it.
Low hydraulic oil level - Checking hydraulic oil level and add if necessary.

Bucket does not function
Bucket controls failure - Check and repair as required.
Hydraulic pump is broken - Repair or change pump if required.
Defective hydraulic control valve - Install a new hydraulic valve or repair it.
Damaged bucket cylinder - Repair or replace cylinder.
Hydraulic fluid is insufficient - Fill up the hydraulic fluid.

Slow boom or bucket operation
Hydraulic pump is worn - Flow-rate pump and change pump if necessary.
Leaking hydraulic cylinder - Install new cylinder seals.
Hydraulic fluid level low - Add fluid as required.
Hydraulic control valve is not set properly or defective - Repair or adjust correctly.
Hydraulic pressure is low - Correct adjustment is required.

Jerky operation of the bucket or boom
Air in hydraulic system - Bleed hydraulic system.
Hydraulic oil filter element is dirty - Clean or change the filter.
Dirty hydraulic fluid - The fluid must be changed.
Cylinder rod or tube is scuffed - Change worn component.

Excessive hydraulic pump noise
Not enough oil or hydraulic system leaking - Refill hydraulic oil or repair leaks in system.
Plugged hydraulic filter - Replace or clean the filter.
Suction line is dirty - Need to service the suction line.
Air enters the pump - Bleed air.
Pump parts are worn out - Rebuild or install new pump.

Electrical Troubleshooting

Battery cannot be charged
Loose or corroded wire connections - Tighten or clean electrical wiring connections.
Electrical terminal connectors are faulty - Terminal connectors should be replaced.
Bad cell in battery - Use a new battery.
Worn or loose belt - Adjust belt tension or replace belt.

Starter motor turns slow
Low battery power - Battery is drained, charge it.
Battery is draining quickly - Battery needs service or replacement.
Bad terminals or disconnected battery cables - Check wiring connections and replace or clean terminals.

Starter will not work
Battery is drained or worn - Recharge or replace battery.
Battery wires are disconnected or incorrectly connected - Check wires and connect correctly.
Battery capacity is low - Recharge the battery.
Starter motor failing - Starter needs to be replaced.